1. Field of the Invention
The present invention relates to a steering switch for a vehicle which is mounted on a steering wheel of an automobile and is served for manipulating various equipment such as an automatic transmission.
2. Discussion of the Related Art
Conventionally, with respect to a steering wheel of an automobile, there has been known a steering wheel which mounts a plurality of steering switches at arbitrary positions. In this type of steering switch, in the midst of traveling in a drive range, an automatic transmission is manually shifted up by rotating a manipulating knob at a neutral position to a back-side from a front side of the steering wheel, while the automatic transmission is manually shifted down by rotating a manipulating knob at a neutral position to the front side from the back side of the steering wheel.
As a conventional steering switch for a vehicle of this type, a steering switch for a vehicle disclosed in Japanese Unexamined Patent Publication 2002-166832 is known.
The conventional steering switch for a vehicle disclosed in this publication includes a support member which is fixed to a central pad of a steering wheel, a manipulating knob which is connected to the support member such that the manipulating knob is rotatable in the front and rear directions of the steering wheel, the manipulating knob projecting inside a space surrounded by the ring of the steering wheel and the pad, biasing means which biases the manipulating knob such that the manipulating knob returns to a neutral position, and signal changeover means which is capable of changing over two kinds of electric signals in response to the rotational direction of the manipulating knob from the neutral position.
A rotary slider is integrally mounted on the manipulating knob, wherein the rotary slider has a shaft hole in which one end of a connecting pin which functions as a rotary shaft of the manipulating knob is inserted and, at the same time, a knob body having a shaft hole in which other end of the connecting pin is inserted is mounted on the manipulating knob. Further, a shaft hole in which an intermediate portion of the connecting pin is inserted is formed in the support member.
That is, with respect to the manipulating knob and the support member, in a state that the support member is arranged between the rotary slider and the knob body, by inserting the connecting pin into respective shaft holes formed in the rotary slider, the support member and the knob body, the manipulating knob is rotatably connected to the support member.
The biasing means includes a recess formed in the knob body, a holder housed in the recess, a spring and a ball housed in the holder, and a cam face formed on a portion of the support member which faces the knob body in an opposed manner, wherein the ball is brought into pressure contact with the cam face due to a repulsive force of the spring so as to make the manipulating knob return to a neutral position.
The signal changeover means includes a printed circuit board which is mounted on the support member and on which conductive patterns made up of a resistance pattern for changing over two kinds of signals and a collector pattern are formed and a slide contact which is mounted on the rotary slider which is rotated along with the rotation of the manipulating knob and slides over the conductive pattern of the printed circuit board.
Further, as the manipulating knob and the support member, there has been known a structure in which two casing members having openings have their openings abut to each other at plural portions using a snap engagement. This structure is configured such that a support structure which rotatably supports the manipulating knob, biasing means and signal changeover means are housed in a hollow formed by two casing members.
As described above, in the conventional steering switch for a vehicle, the printed circuit board of the signal changeover means is mounted on the support member and the slide contact which slides on the printed circuit board is mounted on the rotary slider which is integrally mounted on the manipulating knob. Further, the cam face of the biasing means is formed on the support member and the spring, the ball and the holder are housed in the recess formed in the knob body of the manipulating knob. Further, with respect to the manipulating knob and the support member, by arranging the support member between the rotary slider and the knob body of the manipulating knob and by inserting the connecting pin into the rotary slider, the support member and the knob body respectively, the manipulating knob is rotatably connected to the support member. That is, in the conventional steering switch for a vehicle, at the time of assembling, it is necessary to perform the operation to set the biasing means and the signal changeover means and the operation to mount the manipulating knob to the support member simultaneously, there has been a drawback that the assembling operation becomes complicated.
The present invention has been made in view of the above-mentioned drawbacks of the prior art and it is a first object of the present invention to provide a steering switch for a vehicle which can easily mount a manipulating knob to a support member which is mounted on a steering wheel.
Further, on a steering wheel, besides the above-mentioned steering switch for a vehicle, switches for manipulating various equipment provided to an automobile are mounted. Accordingly, there has been a demand for miniaturization of the steering switch for a vehicle to obviate a drawback that due to mounting of the steering switch for a vehicle to the steering wheel, a mounting space for a plurality of switches is limited.